In recent years, hard disk devices have come to be installed not only in PCs and network servers, but also in consumer electronic appliances, car navigation systems, personal music players, etc., and there is a strong demand for these devices to become quicker and to have a greater capacity. In order to achieve a surface recording density of more than 1 terabit per square inch (around 645.16 square millimeters), it is necessary to improve the stability of the recorded magnetic information to fluctuations in heat. To achieve this, in the situation where conventional media has a flat and continuous shape in the track direction, development has progressed into discrete track-type magnetic recording media in which grooves are formed between tracks to isolate the magnetic recording signals, and bit pattern-type magnetic recording media for magnetic recording onto isolated magnetic particles. Pattern transfer and processing technologies which are employed in methods for producing conventional magnetic heads and semiconductors are applied to the structures of magnetic recording media for which a pattern is formed. In the case of magnetic recording media for hard disk purposes, the magnetic head floats at a spacing of no more than 10 nm, in addition to the abovementioned technology, and technology is used in order to finish the surface of the magnetic media which has undergone pattern processing such that it is smooth, clean, and does not interfere with the floating head.
Japanese Unexamined Patent Application Pub. Nos. H4-309223 and H8-82790 relate to a semiconductor chip and a color filter for a liquid crystal display panel, and these documents disclose a resist removal method in which the resist is removed by ultra-violet (UV) light irradiation employing a low-pressure mercury lamp.
The resist removal method carried out using UV irradiation using a low-pressure mercury lamp requires UV radiation under an ozone atmosphere and high-temperature heating conditions of at least 100° C. in order to promote removal of the whole resist. The effect for removing the resist residue increases in proportion to the ozone gas concentration and the heating temperature, and therefore a high concentration of ozone gas is needed. However, in the case of magnetic recording media, there is a deterioration in the magnetic characteristics during this process, and therefore it is undesirable to expose such media to heating at high temperatures of more than 100° C. and high concentrations of ozone gas. Furthermore, there are limitations to the process, such as that the object from which the resist is being removed can only have the resist removed from the openings fig electrode formation and the unneeded parts outside of the pixels of the color filter, and these methods are not designed for completely removing the resist and carrying out clean processing. This means that such methods may be applied to magnetic recording media, but it is not possible to achieve an adequate removal of the resist residue.
Furthermore, it is desirable to have the head float at a spacing of no more than about 10 nm over the whole surface of the hard disk, and therefore the whole of the surface of the magnetic disk where the pattern is formed needs to be processed uniformly and cleanly, unlike in semiconductor production processes. Therefore, there is a need for a design that includes an alternative method in which the resist residue is removed without any damage to the magnetic film, and the magnetic characteristics and the floating reliability after completion are not adversely affected.